Space telegraphy.



No. 767,994. PATENTED AUG. 16, 1904. v

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No. 797,994. 9 PATENTED AUG. 16, 1994.

J. S. STONE.

SPACE TELEGRAPHY APPLICATION PILBVD FEB. 13, 1904. no MODEL. I 9 SHBETSSHBET z.

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No. 767,994. PATENTED AUG. 16, 1904 J'. S. STONE.

SPACE TELEGRAPHY'.

APFLIUATION FILED FEB.13. 1904.

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No. 767,994. PATENTED AUG. 16', 1904.

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SPACE TELBGRAPHY.

' APPLICATION FILED FEB. 13 1904.

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No. 767,994. PATENTED AUG. 16, 1964. J. s. STONE. SPACE TELEGRAPHY.

APPLIGATION FILED FEB.13, 1904.

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WV big I INJENTEIFY No. 767,994. PATENTED AUG; 16, 1904 J. S. STONE.

SPACE TELEGRAPHY. APPLIGATION FILED FEB. 13, 1904.

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J. s. STONE. SPACE TELEGRAPHY. I APPLICATION FILED FEB. 13, 1904.

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n PERIDI'ZIIEIITY 7 I I I I I I I I l l l l I 1 I I I FZUIIIU UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

JOHN STONE STONE, ()F CAMBRIDGE, hIASSAGI-IUSETTS, ASSIGNOR TO WILLIAM W. SWAN, TRUSTEE, OF BROOKLINE, MASSACHUSETTS.

SPACE. TELEGYRAPHY.

SPECIFICATION forming part of Letters Patent No. 767,994, dated August 16, 1904. Application filed February 13, 190% Serial No. 193,371. (No model.)

To HJ/L whom, it TTbCI/y concern.-

Be it known that I, JOHN STONE STONE, a citizen of the United States, and a resident of Cambridge, in the county of Middlesex and State of Massachusetts, have invented a certain new and useful Improvement in Space Telegraphy, of which the following is a specification. V

This invention relates to the art of transmitting intelligence from one station to another by means of electromagnetic waves without the use of wires to guide the waves to their destination; and it relates more particularly to systems for receiving signals transmitted by such Waves.

The object of the present invention is to so adjust the elevated -conductor system of a wireless or space-telegraph receiving-station relative to an associated tuned or resonant receiving circuit or circuits that, first, a persistent train of electromagnetic. waves of a predetermined frequency impinging upon the elevated conductor shall cause the associated circuit or circuits to respond energetically, that, second, a persistent train of electromag netic waves of frequency other than said predetermined frequency impinging upon the elevated conductor shall cause the associated tuned or resonant circuit or circuits to respond but feebly, and that, third, abrupt or impulsive electric forces acting upon the elevated conductor shall likewise produce but feeble response in the associated tuned or resonant circuit or circuits.

The first and second objects of this invention may be attained by giving the elevatedreceiving-conductor system a pronounced fundamental of a frequency which is the same as I that to which the associated tuned or resonant receiving circuit or circuits is attuned. The first and second objects of this invention may therefore be attained by placing a suitable inductance or capacity in the elevated conductor near its connection to earth if it be an earthed elevated conductor or at the center of a receiving conductor if it be an unearthed conductor, as thereby the receiving-conductor will be given a pronounced and predetermined fundamental much as a stretched string may objects of the invention will be realized; but

this simple device is not suflicient to accomplish the third object of the present invention, and for that purpose it is necessary to give the elevated conductor natural periods of vibration whose frequencies are different from that to which the associated tuned or resonant receiving circuit or circuits is attuned, and this in turn I accomplish by giving the elevated-conductor system a plurality of degrees of freedom, as will hereinafter be more fully described. third object of this invention by employing an elevated-conductor system whose natural rates of vibration are different from the frequency of the waves the energy of which is to be received, and consequently different from the frequency to which the associated tuned or resonant receiving circuit or circuits is attuned.

The invention may be best understood by having reference to the drawings which accompany and form a part of this specification and which illustrate diagrammatically various forms of apparatus and circuit arrangements constituting space-telegraph receiving systems to which the present invention has been applied.

In the drawings, Figures 1 to 20 represent space-telegraph receiving systems. Figs. 21 to 28 are diagrams hereinafter more fully re ferred to in explaining the theory of operation of the systems illustrated in Figs. 1'to 20.

In the figures, V is an elevatedv receivingconductor. E is an earth connection. L is an auxiliary inductance-coil. L1 L are induct- In other words, I accomplish the ances included in series with the elevated conductor and the earth. L1 is an inductance connected in parallel with certain other tuning elements which are serially connected with the elevated conductor. C C are condensers se- 'tector.

riall y included in the resonant circuits. 01 C are condensers included in series with the elevated conductor and the earth. C1 is a condenser connected in parallel with certain other tuning elements which are serially connected with the elevated conductor. NI isa transformer, which may be either a step-up or a ste pdown transformer, according to the character of the receiver or wave-detector employed. 11 I2 are respectively the primary. and secondary windings of transformer l\I. K is a coherer or other suitable receiver or wave-de- K is a bolometer or other receiver. or electroreceptive device adapted to utilize in its operation the dissipative energy of the electrical oscillations developed in the circuit in which it is included. R is a relay or signalindicating device.

In Fig. 1 I have shown one form of the invention herein described applied to a spacetelegraph receiving system whichI have fully described in my Letters Patent Nos. 714,756 and 714,831, dated December 2, '1902. Reference may therefore be had to said Letters Patent for a more complete description of the construction of parts and the operation thereof than is necessary to set forth herein, it being sufiicient to state that by means of the auxiliary inductance L the effect of'the mu tual inductance between the resonant receiving-circuit I2 C" C L and the elevated conductor systemV 11 C1 E is swamped, and the complex of interrelated circuits are therefore reduced to the equivalent of a system of cir- Ccluits each having buta single degree of free- In Fig. 1 I have shown a slightly different arrangement of the battery and relay, which are here included in series with the coil L and the condenser C, the condenser C", which is a condenser of large capacity compared to the condenser O, serving to exclude the relay from the resonant circuit without producing an appreciable effect in the period of the resonant circuit and without appreciably lowering the resonant rise of potential at theterminals of the condenser C.

In Fig. 2 1 have shown another form of the herein-described invention applied to a receiving system which I have described in my Letters Patent Nos. 71 L832 and 71 i, 833,dated December 2, 1-902, and which I have described and claimed in my application, Serial No. 182,632, filed November 25, 1903. In this figure the function of the auxiliary coil L is performed by the transformer M, whose primary and secondary windings have such spatial interrelation as to reduce the complex of interrelated circuits to the equivalent of a system ofcircuits each having a single degree of freedom. The transformer-windings are here diagrammatically shown as parallel; but it is to be understood that this relation is by no means necessary in order to accomplish the desired result, inasmuch as this result may be accomplished if system described in my Letters Patent Nos.

714,832 and 714,833, dated December 2, 1902,

and which show one way in which the function of the auxiliary inductance-coil may be supplied by the secondary winding of the transformer WI. Another way, also described in said Letters Patent, in which the functions of the auxiliary inductance-coil may be performed by the transformer itself is illustrated in Fig. 2, described above. In both cases the principle is the samei. e. the mutual energy of the interrelated circuits is made small compared with the self-energy of each circuit, and this in turn I-accomplish by so designing the transformer that the square of the mutual inductance between its windings is made small compared to the product of the inductance of the primary winding by the inductance of the secondary winding. In the first case the external inductance coil is made part of the transformer-secondary without appreciably increasing the mutual inductance between the windings of the transformer. In the second case the transformer is given sufficient magnetic leakage to effect the desired result 2'. a, the transformer is designed in the manner of a constant-current transformer. The two cases areequivalents, because it is well-' known that external inductance is the equivalent of magnetic leakage in constant-current tran sform ers Fig. 3 corresponds to Fig. 3 and illustrates the same arrangement of battery and relay as is shown in Fig. 1.

In Fig. 4 1 have illustrated another form of the present invention applied to the receiving system described in my application, Serial No. 185,872, filed December 18, 1903. In this system the resonant circuit L L (J is conductively connected to the elevated receiving-conductor by the coil L of inductance small compared to the inductance of the coil L.

Fig. 4: corresponds to Fig. 4 and shows a slightly different arrangement of battery and relay, which in this case are included in series with the coherer K in the manner shown in Fig. 1.

In Fig. 5 I have shown another form of the present invention applied to the receiving system described in my application, SerialNo. 185,873, filed December 18, 1903. In this system the resonant circuit is conductively connected-to the elevated receiving-conductor by means of a condenser C of capacity great compared to the capacity of the condenser C.

Fig. 5 corresponds to Fig. 5 and illustrates the same arrangement of battery and relay as is shown in Fig. I.

In Figs. 6, 7, and 8 I have shown three dilferent embodiments of the herein-described invention applied to the receiving system shown in my Letters Patent Nos. 7 14,7 56 and 714,831. In these cases the resonant circuit M Q" C L is inductively associated with the elevated conductor system and the auxiliary coil L is employed to reduce the complex of interrelated circuits to the equivalent of a system of circuits each having a single degree of freedom.

In Figs. 9 and 10 I have shown two other embodiments of this invention applied to the systems illustrated, respectively, in Figs. 1 and 5".

In Figs. 11 to 18, inclusive, I have,shown several obvious modifications of the broad invention hereinbefore described; but I do not i wish to be understood as confining myself to any of the specific means herein described, as it will be obvious to those skilled in the art that many other combinations of coils and'condensers maybe devised for carrying out the liere nbeforastated objects of this invention, and more particularly do I not wish to be confined to two branch circuits in the elevatedconductor system or to two branch circuits alone, as three or more may be used, as indicated by dotted lines in Figs. 19 and 20; nor do I care to be confined to branch circuits alone, as it will be obvious to those skilled in the art that the loading of the elevated conductor in order to make it responsive to the waves of the frequency to which the local resonant circuit is attuned need not be wholly confined to the branch circuits, but may be in part supplied by a condenser or inductancecoil serially related to the branch circuits, as shown at C1" and L1 in Figs. 19 and 20.

In Figs. 1 to 3, inclusive, the means whereby the natural rates of vibration of the elevated-conductor system is made different from that of the associated resonant receiving-circuit I2. 0 G L is the condenser C1, connected in parallel to the primary winding L of the transformer NI. is the condenser C1, connected in'parallel with the coils L1 and L. In- Figs. 5 and 5 this means is the coil L1, connected in parallel with the condensers C ()1. In Fig. 6 the means employed for accomplishing the hereinbeforestated objects of this invention is the coil L1,

connected in parallel with the condenser 01.

and the primary winding of transformer M. In Fig. 7 the means is the condenser C1, connected in parallel to the condenser C1 and the primary Winding of transformer l\/I. In Fig. 8 the means is the condenser 01', connected in parallel with the coil L1 and the primary wind- In Figs. 1 and this means,

ing of'transformer M. In Fig. 9 the means is the condenser C1, connected in parallel'with the condenser C1 and coil L. In Fig. 10 the means is the condenser C1, connected in parallel with the condenser C and the coil L1. In Figs. 11 and 12 the means are the coils L1, connected in parallel respectively with the condenser C1 and coil L and the condenser C means is the coil-Li", taken in conjunction with the three branch circuits shown in said cuits may be used in this arrangement also.

Careful consideration will show that the branch circuits or other meansemployed for giving the elevated-conductor system natural rates of vibration different from that to which the associated resonant receiving-circuits are responsive, interposed in the vertical wire near its earth connection, will each present a definite inductance or capacity reactance for a predetermined frequency of impressed force and that said reactance will be different for differentfrequencies of the impressed force. If, therefore, the waves to be received are longer than those natural to the elevated conductor per se and the reactance of the elevated conductor per 86 is consequently a capacity reactance, the branch circuits may be so proportioned as to present for the frequency of these waves an inductance reactance equivalent to that which would be given by a loading-coil adapted to make the fundamental of the elevated conductor of a frequency equal to that of the waves to be received. The reactance offered by the elevated-conductor system to the electrical oscillations developed therein by a persistant train of simple harmonic waves the energy of which is to be received is therefore zero. Similarly if the waves to be received are shorter than those natural to the elevated conductor 1907" se and not less than one-half the length of those natural to the elevated conductor the reactance of the elevated conductor per se is consequently an inductance reactance, and the branch circuits may be so proportioned as to present for the frequency of these waves a capacity reactance equivalent to that which would be presented by a loading-condenser adapted to make the fundamental of the elevated conductor of a frequency equal to that of the waves to be received. Here again the reactance oflered by the elevated-conductor system to the electrical oscillations developed figure,although any number of branch cirtherein by a persistent train of simple harmonic waves the energy of which is to be received is zero. I find by experience that when such proportions are given to the constants of the loop-circuits the elevated-conductor-system in responding to abrupt or impulsive electric forces has developed in it natural oscillations of frequencies ill adapted to cause-a response of the associated resonant receiving circuit or circuits, because the frequencies of said natural oscillations are different from the frequency to which said resonant circuit'or circuits is attuned. 1

In explanation of the foregoing reference may be had to Figs. '21 to 28. A circuit consisting of two parallel branches, one of which contains a coil and the other a condenser, when connected in series with a source of simple harmonic electromotive force will present adefinite reactance to the periodically-varying currents developed by said source of electromotive force, and this reactance may be either a capacityreactance or an inductance reactance, depending upon the frequency of the currents. Sucha circuit is shown at Bin Figs. 23, 24, 25, and 26. If the frequency of the currents impressed upon such a circuit is lower than the frequency to which the circuit is resonant when isolated, the reactance of the circuit-is an inductance reactance, while if the-frequency is higher than that to whichthe circuit is resonant when isolated the reactance is a capacity reactance. 1f the frequency be increased beyond that to which the circuit is resonant when isolated and up to infinity, the reactance of the circuit will at all times be a' capacity reactance which will decrease in value until the frequency is infinite, when the reactance vanishes. This may be best understood by having reference" to Fig. 23 which is a curve drawn to rectangular coordinates, in which the ordinates represent the-reactance of the circuit, as described, and the abscissae represent the periodicity (or 2 rn)of the impressed electromotive force.- The frequency to which this circuit is resonant is indicated in the figure at point m. This, however, isnot true of a circuit whose inductance-is distributed inductance and whose capacity is distributed capacity'such, for example, as the elevated conductor per se of the systems described herein. vated conductors the reactance for low frequencies of impressed force is a capacity reactan'ce. As the frequency-is increased the reactance decreases until the frequency becomes equal to the fundamental frequency of such conductor, at which 'point the reactance becomes Zero. For any increase of frequency beyond this point the reactance becomes an inductance reactance rising to a maximum value. f At twicethe fundamental frequency the reactance again becomes a capacity reactance and diminishes as the frequency is further increased until the frequency is equal tothe first odd harmonic of the fundamental For such ele-I frequency, when the reactance again becomes zero. Forfurther increase in frequency from this point the reactance again becomes an inductance reactance, rising to a maximum value. At four times the fundamental frequency the reactance again changes to a ca pacity reactance and wanes as the frequency is further increased until the frequency is equal to the second odd harmonic of the fun damental frequency, when the reactance again becomes zero. The reactance of such a conductor is illustrated at Fig. 21, which is a curve drawn to rectangular coordinates, in which the ordinates represent the reactance at the center of the conductor and the abscissae represent the periodicity of the impressed force.

Attention is drawn to the fact that the reactance of the conductor is zero at the points in" m, these points corresponding, respectively, to the fundamental of the vertical conductor andits first odd harmonic.

As a consequence of the mode of variation of reactance with frequency (shown in Fig. 21) the curve showing the variation with frequency of currents developed in an elevated conductor, exhibits several maxima, one for the fundamental frequency m of said elevated conductor and one for each odd harmonic frequency m", &c., as indicated in Fig. 22, where the ordinates represent the intensities of current and the abscissae represent periodicities.

As hereinbefore stated, the first and second objects of this invention may be attained by giving the elevated-conductor system a pronounced fundamental of a frequency which is the same as that to which the associated resonant receiving circuit or circuits is attuned. If, therefore, the waves to be received are longer than those natural to the elevated conductor per se@'. 0., if the frequency of these waves is less than the fundamental frequency of the elevated conductor per se, and the elevated conductor per 86 therefore offers a capacity reactance to the electrical oscillations developed in said elevated conductor a loading-coiloffering to oscillations of this frequency the proper inductance reactance inserted in the elevated conductor as hereinbefore specified will make the fundamental of the elevated-conductor system of a frequency equal to that of the waves to be received. In like manner'a loading condenser may be employed to balance the inductance reactance of the elevated conductor per 86 if the waves to fundamental to the frequency at of the waves to be received by such means, electromagnetic waves of different frequencies and of great intensity or abrupt or impulsive electric forces impinging upon the elevated conductor will. cause the elevated-conductor system to vibrate at its fundamental rate. In other words, there will be developed in such elevated-conductor system electrical oscillations of frequency 72/. If, therefore, the associated resonant circuit be made resonant to said frequency 12 electrical oscillations of the corresponding frequency to which it is made resonant will be developed therein and will effect the response of the receiver or wave-detector. It is for this reason that I do not employ a loadingcoil or a loading-condenser to attune the fundamental of the elevated-conductor system to the frequency of the waves to be received 2'. 6., to the frequency of the waves to which the associated resonant receiving-circuit is made resonant. However, by balancing the reactance of the elevated conductor per 86 by the reactanceof the various combinations of coils and condensers described in this application, which combinations of coils and condensers offer an inductance reactance or a capacity reactance for the frequency of the waves to be received equivalent, respectively, to that of a loading-coil or a loading-condenser adapted to make the fundamental of the elevated conductor of a frequency equal to that of the waves to be received, the natural electrical oscillations developed in said elevatedconductor system by intense electromagnetic waves of frequencies to which the associated resonant receiving-circuit is not resonant or by abrupt or impulsive electric forces are either of lower frequency or of higher frequency than that to which such associated resonant receiving-circuit is responsive, and thus but feeble currents are developed in the resonant receiving-circuit and the receiver is not affected. In explanation of this, attention is called to the fact that, as hereinbefore stated, the third object of this invention is accomplished by giving theelevated-conductor system a plurality of degrees of freedomi. 6., by giving said elevated -.conductor system natural rates of vibration different from the frequency of the waves the energy of which is to be received, and consequently different from the frequency to which the resonant receiving-circuit is made resonant. 1

The term plurality of degrees of freedom is used herein as it was used by me'in my United States Letters Patent No. 714,756,

December 2, 1902, and No. 737,170, August 25, 1903, to which reference may be had.

In Figs. 24 and 25 I have illustrated systems A B of at least three degrees of freedom, each inductively associated with a resonant circuit D, and in Fig. 26 I have illustrated an elevated-conductor system A B of at least three degrees of freedom inductively associated with a resonant receiving-circuit D.

In Figs. 2 1 and 25 A is a-circnit containing a condenser and an inductance-coil and having a fundamental natural frequency when conductively connected with circuit B, (represented by n".) B is a circuit containing a condenser and an inductance-coil and having a natural fundamental frequency when conductively connected with circuit A, (represented by n.) D is a resonant circuit inductively associated with the system A B. The mutual inductance between the circuit D and the system A B is made small, so that the natural periods of circuit D and of the system A B will not be materiallyaffected by their association.

WVhen the two circuits A and B are associated by conductive connections, a system of three degrees of freedom results, and in the natural oscillatory restoration to electrical equilibrium of such a system the currents are not of a single frequency, but consist of a superposition of at least two currents of different frequencies, each of fwhich currents is found in each of the circuits A and B of the conductively connected system. If, therefore, the natural period of the resonator-circuit D be varied from zero to infinity, the curve showing the variation with frequency of the intensity of' the currents developed in the circuit D by the natural oscillatory restoration to electrical equilibrium of the system A B will exhibit at least two maxima, one of which will correspond to frequency n and another to frequency 01 as shown in Fig. 24.

this frequency circuit A offer a capacity re-.

actance, and if for oscillations of this frequency circuit B offer an inductance reactance equivalent to that of a loading-coil adapted to make the fundamental frequency of the system A B equal to the frequency n of the impressed force, then the reactance of the system A B for forced electrical oscillations of frequency 71- will be zero, currents of maximum amplitude of frequency a will be developed in circuit D, and the curve showing the variation with frequency of currents in circuit D will .exhibit but a single maximum, which will correspond to frequency n, as indicated in Fig. 25

In Fig. 26 I have illustrated one system for carrying out the principle above explained;

IIO

Thi's system is thesame as'th'at illustrated in Fig. 1 of this application. The circuit A is an elevated conductor which may be considered as thecircuitA in Fig. 24, elevated and extended so as tohave by virtue of its distributed inductance and its distributedcapacity the same capacity reactance for Oscillations of frequency n as circuit A. in Figs. 24 and 25 and tohave a fundamental equal to the natural period of circuit A. The fundamental frequency of the elevated conductor A when conductii'ely connected with circuit B is, as before, a? The circuit B of Fig. 26 corresponds to circuits B of Figs. 24 and 25 and its natural frequency when conductively connected with circuit A is, as before, 11/. The circuitD is a resonant receiving -circuit attuned to frequency n, and this circuit corresponds to the resonator-circuit D of Figs. 24 and 25.

If a persistent train of electromagnetic waves of frequency 12 create forced electrical oscillations of like frequency in the elevatedconductor system A B, if for electrical oscillations of this frequency the circuit A offer a capacity reactance, and if for oscillations of this frequency the circuit B offer an inductance reactan'ce equivalent to that of a loadingco'il adapted to make the fundamental frequency of the system A B equal to the frequency n of the impressed force, then the reactanceof the system A B for forced oscillations of frequency n will-be zero, currents of maximum amplitude of frequency n will be developed in circuit D, and the curve showing the variation with frequency of the currents developed in circuit D will exhibit but period of the associated resonant circuitD be correspondingly varied, two maxima will be observed in the currents in circuit D, one at frequency 72 and the other at frequency n, as shown at Fig. 26, which is a curve drawn to rectangular coordinates, in which the ordinates represent currents in the circuit D and abrupt or impulsive electric forces a by far greater amount of energy is absorbed and redistributed by said natural oscillations which, as shown in Fig. 26, are of frequencies different from that to which the associated resonant circuit is attuned and that therefore said resonant circuit is not affected bysuch abrupt or impulsive electric forces.

The curves herein represented in Figs. 21, 22, 242, 25, and 26, though not drawn to scale, are nevertheless based upon curves drawn from computations made, which computations have been verified by actual experiments both in the laboratory and between two stations twelve miles apart.

The curve represented in Fig. 27 shows the variation of the various reactances hereinbefore referred to with frequency. In this curve n represents the frequency of the waves the energy of which is to be received, being thefrequency of the associated resonant circuit'. 7% is the frequency to which the loopcircuit B would be resonant if isolated. n1 is the natural rate of vibration of the vertical when isolated. n" is the natural period of the elevated conductor as affected by its associationwith the loop-circuit B.

The curve represented in Fig. 28 shows the amplitudes of the currents developed in the elevated conductor which correspond to various frequencies of impressed force.

While I have discussed in the foregoing a very simple case involved in that embodiment of the here'indescribed invention which is illustrated in Fig. 1, it will be understood.

quency of the, waves the energy of which is to be received, and an elevated receivin'gcon ductor systemassociated with said resonant circuit and attuned-as to. its natural rates of vibration to frequencies different from that of the associated resonant circuit."

' receiving-circuit.

3. In a space-telegraph receiving system, a resonant receivingecircuit', attuned to the frequency of the waves the energy of which is to be received, an elevated receiving conductor associated with said resonant circuit, and means for giving to said elevated conductor natural rates of vibration difl erent from that of said associated resonant circuit. I

4. In a space-telegraph receiving system, a receiving-circuit, attuned by capacity and inductance to the frequency of the waves, the energy of which is to be received, an elevated receiving-conductor associated with said tuned receiving-circuit, and means for giving to said elevated conductor natural rates of vibration different from that of said tuned receivingcircuit.

5. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, and an elevated receiving-conductor system inductively associated with said resonant circuit and attuned as to its natural rates of vibration to frequencies different from that of the resonant circuit.

6. In a space-telegraph receiving system, a receiving-circuit, attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, and an elevated receiving-conductor system, inductively associated with said receiving-circuit and attuned as to its natural rates of vibration to frequencies different from that of the tuned receiving-circuit.

7. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, an elevated receiving conductor inductively associated with said resonant circuit and means for giving to said elevated conductor natural rates of vibration different from that'of said resonant circuit.

8. In a space-telegraph receiving system, a receiving-circuit, attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, an elevated receiving-conductor inductively associated with said receiving-circuit and means for givingto said elevated conductor natural rates of vibration different from that of said tuned receiving-circuit.

9. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, an elevated receiving-conductor system associated with said resonant circuit and attuned as to its natural rates of vibration to frequencies diflerent from that of the associated resonant circuit and means for swamping the effect of the mutual inductance between the elevated-conductor system and the resonant circuit. 7

10. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, an elevated receiving-conductor system associated with said resonant circuit and attuned as to its natural ratesof vibration to frequencies different from that of the associated resonant circuit, and an auxiliary inductance-coil for swamping the effect of the mutual inductance between theelevatedconductor system and the resonant circuit.

11. In a system of space telegraphy, an ele' vated receiving-conductor serially connected to the primary winding of a transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary windnected. in parallelwith the primary winding of said transformer, said condenser being so designed as to give to said elevated conductor natural rates of vibration different from that of the resonant circuit.

12. In a system of space telegraphy, an-elevated receiving-conductor serially connected to the primary winding of a transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer, acondenser connected in parallel with the primary winding of the said transformer, said condenser being so designed as to give to said elevated conductor natural rates of vibration difierent from that of the resonant circuit, and means for swamping the effectof the mutual inductance between the elevated conductor and the resonant circuit.

13. In a system of space telegraphy, an elevated receiving-conductor, serially connected to the primary winding of a transformer, a resonant receiving-circuit, attuned to the frequency ofthe waves the energy of which is to be received, including the secondary winding of the said transformer, a condenser connected in parallel with the primary winding of said transformer, said condenser being so designed as to give said elevated conductor natural rates of vibration difierent from that of the resonant circuit, and anauxiliary inductance-coil for swamping the effect of the mutual inductance between the elevated conductor and the resonant circuit.

14. As a means for preventing a tunedreceiving-circuit of a space-telegraph receiving system from responding to extraneous electrical impulses of a frequency to which the circuit is not attuned or to abrupt or impulsive electrical forces,.a tuned receiving-circuit and means whereby the elevated receiving-conductor is given natural rates of vibration different from that ofthe associated tuned receiving-circuit. i

15.. In a system of space telegraphy, an elevated receiving-conductor serially connected to the primary winding of a stepuptran.' former, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer and a condenser connected in parallel with the primary winding of the transformer, said condenser being so designed as to give to said elevated conductor natural rates of vibration different from that of the resonant circuit.

16. In a system of space telegraphy, an elevated receiving-conductor serially connected to the primary winding of a step-down transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer and a coning of said transformer, and a condenser con- 1, denser connected in parallel with the primarywinding of the transformer, said condenser being so deslgned as to give to sald elevated conductor natural rates of vibration different to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer, a condenser connected in parallel with the primarywinding of the" transformer, said condenser being so designed as to give to said elevated conductorn'atural rates of vibration different from that of the resonant circuit, and means for swamping the effect of the mutual inductance between the elevated conductor and the resonant circuit.

18. In asystem of space telegraphy, an elevated receiving-conductor, serially connected to the primary winding of a step-down transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer, a condenser connected in parallel with the primary wind ing of the transformer, said condenser being so designed as to give to said elevated conductor natural rates of vibration different from that of the resonant circuit, and means for swamping the effectof the mutual inductance between the elevated conductor and the resonant circuit.

19. In a system of space telegraphy, an elevated receiving-conductor serially connected to the primary winding of a step-up transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary winding of said transformer, a condenser connected in parallel with the primary winding of the transformer, the said condenser being so designed as to give said elevated conductor natural rates of vibration different from that of the resonant circuit, and an auxiliary inductance-coil for swamping the effect the mutual inductance between the elevated conductor and the resonant circuit.

20. In asystem of space telegraphy, an elevated receiving-conductor serially connected to the primary Winding of a step-down transformer, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, including the secondary Winding of said transformer, a condenser connected in parallel with the primary Winding of the transformer, the said condenser being so designed as to give said elevated conductor natural rates of vibration different from that of the resonant circuit, and an auxiliary inductance-coil for swamping the effect of the mutual inductance between the elevated conductor and the resonant circuit.

21. In a system of space telegraphy, an elevated receiving-conductor and a tuned receiving-circuit associated therewith, in combination with means for preventing said tuned receiving-circuit from responding to extraneous electrical impulses of a frequency to which said circuit is not attuned, or to abrupt or impulsive electrical forces.

22. In a system of space telegraphy, an elevated receiving-conductor anda resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, associated therewith, in combination with means for preventing said resonant receiving-circuit from responding to extraneous electrical impulses of a frequency to which said resonant receiving-circuit is not attuned, or to abrupt or impulsive electrical forces.

I 23. As a means for preventing a resonant receiving-circuit of a space-telegraph receiving system from responding to extraneous electrical impulses of a frequency to which the resonant circuit is not attuned or to abrupt or impulsive electrical forces, a resonant circuit, attuned to the frequency of thewaves the energy of which is to be received, and means whereby the elevated receiving-conductor is given natural rates of vibration different from that of'the' associated resonant.

receiving-circuit.

24. In a space-telegraph receiving system, an elevated receiving-conductor in combination with means whereby said elevated conductor is given natural rates of vibration different from the frequency of electromagnetic waves the energyof which is to be received, and a tuned receiving-circuit associated with said elevated conductor.

25. In a space-telegraph receiving system, an elevated receiving-conductor in combination with means whereby said elevated conductor is given natural rates of vibration different from the frequency of electromagnetic waves the energy of which is to be received, and a resonant receiving-circuit, attuned to the frequency of said waves and associated with said elevated conductor.

26. In a space-telegraph receiving system,

a receiving-circuit, attuned by capacity and in ductance to the frequency of the waves the energy of which is to be received, and an elevated receiving-conductor associated with said receiving-circuit and adapted to present for said frequency a capacity reactance, in combination with means comprising coils, or condensers, or both, associated with said elevated conductor and so designed as to present for said frequency an inductance reactance equivalent to that which would be given by a loading-coil adapted to make the fundamental of said elevated conductor of a frequency equal to the frequency of the waves to be received.

27. In a space-telegraph receiving system, a receiving-circuit, attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, and an elevatcd receiving-conductor associated with said receiving-circuit and adapted to present for said frequency an inductance reactance, in combination with means including coils, or condensers, or both, associated with said elevated conductor and so designed as to present for said frequency a capacity reactance equivalent to that which would be presented by a loading-condenser adapted to make the fundamental of said elevated conductor of a frequency equal to the frequency of the waves to be received.

28. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, and an elevated receivingconductor associated with said resonant receiving-circuit and adapted to present for said frequency a capacity reactance, in combination with means comprising coils, or condensers, or both, associated with said elevated conductor and so designed as to present for said frequency an inductance reactance equivalent to that which would be given by a loading-coil adapted to make the fundamental of Said elevated conductor of a frequency equal to the frequency of the waves to be received.

29. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, and an elevated receivingconductor associated with said resonant receiving-circuit and adapted to present for said frequency an inductance reactance, in combination with means including coils, or condensers, or both, associated with said elevated conductor and so designed as to present for theses inclosing shown in Fig. 21

[SEAL-1 tor-muons in Letters Patent No. 767,994.

It is hereby certified that in- Letters Patent N o. 7 67 upon the application of John Stone Stone of Cambridge, ment in Space Telegraphy, errors appear in the printed specification requiring correction, as follows: On page 2, line 33, the word 50,-the period after I, should be stricken out 74-75, same page, the parentheses inclosin out; and that the said Letters Patent should be read with the that the same may conform to the record of the case in the Iatent Ofiice.

, Signed and sealed this 11th day of July, A. 1)., 1905.

said frequency a capacity reactance equiva lent to that which would be presented by a loading-condenser adapted to make the funda mental of said elevated conductor of a frequency equal to the frequency of the waves to be received.

30. In a space-telegraph receiving system, an elevated-conductor system having a plurality of degrees of freedom, a tuned receiving-circuit associated therewith, and means for reducing the complex of interrelated circuits so formed to the equivalent of a system of a single degree of freedom.

31. In a space-telegraph receiving system, an elevated-conductor system having a plurality of degrees of freedom, a tuned receiving-circuit associated therewith, and means for eliminating the effect on the natural period of the associated tuned receiving-circuit of its association with said elevated-conductor system.

32. In a space-telegraph receiving system, a receiving-circuit attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, in combination with means for preventing said circuit from responding to electrical impulses of a frequency to which it is not attuned, or to abrupt or impulsive electrical forces.

In testimony whereof I have hereunto subscribed my name this 11th day of February,

JOHN STONE STONE.

Witnesses:

BRAINERD T. JUDKINS, G. ADELAIDE HIGGINS.

F. I. ALLEN,

Commissioner of Patents.

and in line 112, a comma or on page 5, lines -7Tl,

n should be stricken out, and in lines g represented by n should be stricken se corrections therein ,994, granted August 16, 1904, Massachusetts, for an improveare should read is; on page 3, line on page 4, lines 89-90, the parenshould be stricken out should be substituted for the dash after the word conduct the parentheses inclosing represented by vatcd receiving-conductor associated with said receiving-circuit and adapted to present for said frequency an inductance reactance, in combination with means including coils, or condensers, or both, associated with said elevated conductor and so designed as to present for said frequency a capacity reactance equivalent to that which would be presented by a loading-condenser adapted to make the fundamental of said elevated conductor of a frequency equal to the frequency of the waves to be received.

28. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, and an elevated receivingconductor associated with said resonant receiving-circuit and adapted to present for said frequency a capacity reactance, in combination with means comprising coils, or condensers, or both, associated with said elevated conductor and so designed as to present for said frequency an inductance reactance equivalent to that which would be given by a loading-coil adapted to make the fundamental of Said elevated conductor of a frequency equal to the frequency of the waves to be received.

29. In a space-telegraph receiving system, a resonant receiving-circuit, attuned to the frequency of the waves the energy of which is to be received, and an elevated receivingconductor associated with said resonant receiving-circuit and adapted to present for said frequency an inductance reactance, in combination with means including coils, or condensers, or both, associated with said elevated conductor and so designed as to present for theses inclosing shown in Fig. 21

[SEAL-1 tor-muons in Letters Patent No. 767,994.

It is hereby certified that in- Letters Patent N o. 7 67 upon the application of John Stone Stone of Cambridge, ment in Space Telegraphy, errors appear in the printed specification requiring correction, as follows: On page 2, line 33, the word 50,-the period after I, should be stricken out 74-75, same page, the parentheses inclosin out; and that the said Letters Patent should be read with the that the same may conform to the record of the case in the Iatent Ofiice.

, Signed and sealed this 11th day of July, A. 1)., 1905.

said frequency a capacity reactance equiva lent to that which would be presented by a loading-condenser adapted to make the funda mental of said elevated conductor of a frequency equal to the frequency of the waves to be received.

30. In a space-telegraph receiving system, an elevated-conductor system having a plurality of degrees of freedom, a tuned receiving-circuit associated therewith, and means for reducing the complex of interrelated circuits so formed to the equivalent of a system of a single degree of freedom.

31. In a space-telegraph receiving system, an elevated-conductor system having a plurality of degrees of freedom, a tuned receiving-circuit associated therewith, and means for eliminating the effect on the natural period of the associated tuned receiving-circuit of its association with said elevated-conductor system.

32. In a space-telegraph receiving system, a receiving-circuit attuned by capacity and inductance to the frequency of the waves the energy of which is to be received, in combination with means for preventing said circuit from responding to electrical impulses of a frequency to which it is not attuned, or to abrupt or impulsive electrical forces.

In testimony whereof I have hereunto subscribed my name this 11th day of February,

JOHN STONE STONE.

Witnesses:

BRAINERD T. JUDKINS, G. ADELAIDE HIGGINS.

F. I. ALLEN,

Commissioner of Patents.

and in line 112, a comma or on page 5, lines -7Tl,

n should be stricken out, and in lines g represented by n should be stricken se corrections therein ,994, granted August 16, 1904, Massachusetts, for an improveare should read is; on page 3, line on page 4, lines 89-90, the parenshould be stricken out should be substituted for the dash after the word conduct the parentheses inclosing represented by I h V I r oert ifled that in Letters Patent No. 767,994, granted August 16', 1904,

ofJolm, Stone Stone of Cambridge, Massachusetts, for an improvement in Space Telegraphy,

errors appear in the printed specification requiring 001'- v rection, as follows: On page 2, line 33, the word are should read is; on page 3, line 7 Q 50, the period after I, age 4, lines 89-90, the paren- T should be stricken out, au d'in line 112, a comma fter the word conductor on page 5, lines 70-71, represented bynf should be stricken out, and in lines 75, same page, the parentheses inclosing represented by n should stricken k t; and that the said Letters Patent should be read with these oorrecju'ous therein at the same may conform to the record of the case in the l atent Oflice. Signed and sealed this 11th day of July, A. D., 1905. l [emu] should be stricken out; on p #heses inclosing shown in Fig. 21 1 ould substituted for the dash a e parentheses inclosing 

